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181 <div class=
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182 <h1>libmemcached Examples
<a class=
"headerlink" href=
"#libmemcached-examples" title=
"Permalink to this headline">¶
</a></h1>
183 <p>Examples for libmemcached
</p>
184 <div class=
"section" id=
"description">
185 <h2>DESCRIPTION
<a class=
"headerlink" href=
"#description" title=
"Permalink to this headline">¶
</a></h2>
186 <p>For full examples, test cases are found in tests/*.c in the main distribution.
187 These are always up to date, and are used for each test run of the library.
</p>
189 <div class=
"section" id=
"connecting-to-servers">
190 <h2>Connecting to servers
<a class=
"headerlink" href=
"#connecting-to-servers" title=
"Permalink to this headline">¶
</a></h2>
191 <div class=
"highlight-c notranslate"><div class=
"highlight"><pre><span></span><span class=
"k">const
</span> <span class=
"kt">char
</span> <span class=
"o">*
</span><span class=
"n">config_string
</span> <span class=
"o">=
</span>
192 <span class=
"s">"--SERVER=host10.example.com
"</span>
193 <span class=
"s">"--SERVER=host11.example.com
"</span>
194 <span class=
"s">"--SERVER=host10.example.com
"</span><span class=
"p">;
</span>
195 <span class=
"n">memcached_st
</span> <span class=
"o">*
</span><span class=
"n">memc
</span><span class=
"o">=
</span> <span class=
"n">memcached
</span><span class=
"p">(
</span><span class=
"n">config_string
</span><span class=
"p">,
</span> <span class=
"n">strlen
</span><span class=
"p">(
</span><span class=
"n">config_string
</span><span class=
"p">);
</span>
196 <span class=
"p">{
</span>
197 <span class=
"c1">// ...
</span>
198 <span class=
"p">}
</span>
199 <span class=
"n">memcached_free
</span><span class=
"p">(
</span><span class=
"n">memc
</span><span class=
"p">);
</span>
202 <p>In the above code you create a
<a class=
"reference internal" href=
"memcached_create.html#_CPPv412memcached_st" title=
"memcached_st"><code class=
"xref cpp cpp-any docutils literal notranslate"><span class=
"pre">memcached_st
</span></code></a> object with three server by making
203 use of
<a class=
"reference internal" href=
"memcached_create.html#_CPPv416memcached_createP12memcached_st" title=
"memcached_create"><code class=
"xref cpp cpp-any docutils literal notranslate"><span class=
"pre">memcached_create()
</span></code></a>.
</p>
205 <div class=
"section" id=
"creating-a-pool-of-servers">
206 <h2>Creating a pool of servers
<a class=
"headerlink" href=
"#creating-a-pool-of-servers" title=
"Permalink to this headline">¶
</a></h2>
207 <div class=
"highlight-c notranslate"><div class=
"highlight"><pre><span></span><span class=
"k">const
</span> <span class=
"kt">char
</span> <span class=
"o">*
</span><span class=
"n">config_string
</span> <span class=
"o">=
</span>
208 <span class=
"s">"--SERVER=host10.example.com
"</span>
209 <span class=
"s">"--SERVER=host11.example.com
"</span>
210 <span class=
"s">"--SERVER=host10.example.com
"</span><span class=
"p">;
</span>
212 <span class=
"n">memcached_pool_st
</span><span class=
"o">*
</span> <span class=
"n">pool
</span><span class=
"o">=
</span> <span class=
"n">memcached_pool
</span><span class=
"p">(
</span><span class=
"n">config_string
</span><span class=
"p">,
</span> <span class=
"n">strlen
</span><span class=
"p">(
</span><span class=
"n">config_string
</span><span class=
"p">));
</span>
214 <span class=
"n">memcached_return_t
</span> <span class=
"n">rc
</span><span class=
"p">;
</span>
216 <span class=
"n">memcached_st
</span> <span class=
"o">*
</span><span class=
"n">memc
</span><span class=
"o">=
</span> <span class=
"n">memcached_pool_pop
</span><span class=
"p">(
</span><span class=
"n">pool
</span><span class=
"p">,
</span> <span class=
"nb">false
</span><span class=
"p">,
</span> <span class=
"o">&</span><span class=
"n">rc
</span><span class=
"p">);
</span>
218 <span class=
"c1">// .... do work
</span>
220 <span class=
"cm">/*
</span>
221 <span class=
"cm"> Release the memc_ptr that was pulled from the pool
</span>
222 <span class=
"cm">*/
</span>
223 <span class=
"n">memcached_pool_push
</span><span class=
"p">(
</span><span class=
"n">pool
</span><span class=
"p">,
</span> <span class=
"n">memc
</span><span class=
"p">);
</span>
225 <span class=
"cm">/*
</span>
226 <span class=
"cm"> Destroy the pool.
</span>
227 <span class=
"cm">*/
</span>
228 <span class=
"n">memcached_pool_destroy
</span><span class=
"p">(
</span><span class=
"n">pool
</span><span class=
"p">);
</span>
231 <p>In the above code you create a
<a class=
"reference internal" href=
"../libmemcachedutil/memcached_pool.html#_CPPv417memcached_pool_st" title=
"memcached_pool_st"><code class=
"xref cpp cpp-any docutils literal notranslate"><span class=
"pre">memcached_pool_st
</span></code></a> object with three server by
232 making use of
<a class=
"reference internal" href=
"../libmemcachedutil/memcached_pool.html#_CPPv414memcached_poolPKc6size_t" title=
"memcached_pool"><code class=
"xref cpp cpp-any docutils literal notranslate"><span class=
"pre">memcached_pool()
</span></code></a>.
</p>
233 <p>When
<a class=
"reference internal" href=
"../libmemcachedutil/memcached_pool.html#_CPPv422memcached_pool_destroyP17memcached_pool_st" title=
"memcached_pool_destroy"><code class=
"xref cpp cpp-any docutils literal notranslate"><span class=
"pre">memcached_pool_destroy()
</span></code></a> all memory will be released that is associated
236 <div class=
"section" id=
"adding-a-value-to-the-server">
237 <h2>Adding a value to the server
<a class=
"headerlink" href=
"#adding-a-value-to-the-server" title=
"Permalink to this headline">¶
</a></h2>
238 <div class=
"highlight-c notranslate"><div class=
"highlight"><pre><span></span><span class=
"kt">char
</span> <span class=
"o">*
</span><span class=
"n">key
</span><span class=
"o">=
</span> <span class=
"s">"foo
"</span><span class=
"p">;
</span>
239 <span class=
"kt">char
</span> <span class=
"o">*
</span><span class=
"n">value
</span><span class=
"o">=
</span> <span class=
"s">"value
"</span><span class=
"p">;
</span>
240 <span class=
"kt">time_t
</span> <span class=
"n">expires
</span> <span class=
"o">=
</span> <span class=
"mi">0</span><span class=
"p">;
</span>
241 <span class=
"kt">uint32_t
</span> <span class=
"n">flags
</span> <span class=
"o">=
</span> <span class=
"mi">0</span><span class=
"p">;
</span>
243 <span class=
"n">memcached_return_t
</span> <span class=
"n">rc
</span> <span class=
"o">=
</span> <span class=
"n">memcached_set
</span><span class=
"p">(
</span><span class=
"n">memc
</span><span class=
"p">,
</span>
244 <span class=
"n">key
</span><span class=
"p">,
</span> <span class=
"n">strlen
</span><span class=
"p">(
</span><span class=
"n">key
</span><span class=
"p">),
</span>
245 <span class=
"n">value
</span><span class=
"p">,
</span> <span class=
"n">value_length
</span><span class=
"p">,
</span>
246 <span class=
"n">expires
</span><span class=
"p">,
</span> <span class=
"n">flags
</span><span class=
"p">);
</span>
248 <span class=
"k">if
</span> <span class=
"p">(
</span><span class=
"n">rc
</span> <span class=
"o">!=
</span> <span class=
"n">MEMCACHED_SUCCESS
</span><span class=
"p">)
</span>
249 <span class=
"p">{
</span>
250 <span class=
"c1">// handle failure
</span>
251 <span class=
"p">}
</span>
254 <p>It is best practice to always look at the return value of any operation.
</p>
256 <div class=
"section" id=
"fetching-multiple-values">
257 <h2>Fetching multiple values
<a class=
"headerlink" href=
"#fetching-multiple-values" title=
"Permalink to this headline">¶
</a></h2>
258 <div class=
"highlight-c notranslate"><div class=
"highlight"><pre><span></span><span class=
"n">memcached_return_t
</span> <span class=
"n">rc
</span><span class=
"p">;
</span>
259 <span class=
"kt">char
</span> <span class=
"o">*
</span><span class=
"n">keys
</span><span class=
"p">[]
</span><span class=
"o">=
</span> <span class=
"p">{
</span><span class=
"s">"fudge
"</span><span class=
"p">,
</span> <span class=
"s">"son
"</span><span class=
"p">,
</span> <span class=
"s">"food
"</span><span class=
"p">};
</span>
260 <span class=
"kt">size_t
</span> <span class=
"n">key_length
</span><span class=
"p">[]
</span><span class=
"o">=
</span> <span class=
"p">{
</span><span class=
"mi">5</span><span class=
"p">,
</span> <span class=
"mi">3</span><span class=
"p">,
</span> <span class=
"mi">4</span><span class=
"p">};
</span>
261 <span class=
"kt">unsigned
</span> <span class=
"kt">int
</span> <span class=
"n">x
</span><span class=
"p">;
</span>
262 <span class=
"kt">uint32_t
</span> <span class=
"n">flags
</span><span class=
"p">;
</span>
264 <span class=
"kt">char
</span> <span class=
"n">return_key
</span><span class=
"p">[
</span><span class=
"n">MEMCACHED_MAX_KEY
</span><span class=
"p">];
</span>
265 <span class=
"kt">size_t
</span> <span class=
"n">return_key_length
</span><span class=
"p">;
</span>
266 <span class=
"kt">char
</span> <span class=
"o">*
</span><span class=
"n">return_value
</span><span class=
"p">;
</span>
267 <span class=
"kt">size_t
</span> <span class=
"n">return_value_length
</span><span class=
"p">;
</span>
269 <span class=
"n">rc
</span><span class=
"o">=
</span> <span class=
"n">memcached_mget
</span><span class=
"p">(
</span><span class=
"n">memc
</span><span class=
"p">,
</span> <span class=
"n">keys
</span><span class=
"p">,
</span> <span class=
"n">key_length
</span><span class=
"p">,
</span> <span class=
"mi">3</span><span class=
"p">);
</span>
271 <span class=
"n">x
</span><span class=
"o">=
</span> <span class=
"mi">0</span><span class=
"p">;
</span>
272 <span class=
"k">while
</span> <span class=
"p">((
</span><span class=
"n">return_value
</span><span class=
"o">=
</span> <span class=
"n">memcached_fetch
</span><span class=
"p">(
</span><span class=
"n">memc
</span><span class=
"p">,
</span> <span class=
"n">return_key
</span><span class=
"p">,
</span> <span class=
"o">&</span><span class=
"n">return_key_length
</span><span class=
"p">,
</span>
273 <span class=
"o">&</span><span class=
"n">return_value_length
</span><span class=
"p">,
</span> <span class=
"o">&</span><span class=
"n">flags
</span><span class=
"p">,
</span> <span class=
"o">&</span><span class=
"n">rc
</span><span class=
"p">)))
</span>
274 <span class=
"p">{
</span>
275 <span class=
"n">free
</span><span class=
"p">(
</span><span class=
"n">return_value
</span><span class=
"p">);
</span>
276 <span class=
"n">x
</span><span class=
"o">++
</span><span class=
"p">;
</span>
277 <span class=
"p">}
</span>
280 <p>Notice that you freed values returned from memcached_fetch(). The define
281 <code class=
"xref cpp cpp-any docutils literal notranslate"><span class=
"pre">MEMCACHED_MAX_KEY
</span></code> is provided for usage.
</p>
283 <div class=
"section" id=
"see-also">
284 <h2>SEE ALSO
<a class=
"headerlink" href=
"#see-also" title=
"Permalink to this headline">¶
</a></h2>
286 <div><p><em class=
"manpage"><a class=
"manpage reference external" href=
"http://man7.org/linux/man-pages/man1/memcached.1.html">memcached(
1)
</a></em></p>
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"rst-footer-buttons" role=
"navigation" aria-label=
"footer navigation">
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"versioning.html" class=
"btn btn-neutral float-right" title=
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